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Old 14th Jul 2021, 10:35 pm   #61
Red to black
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Default Re: GEC BT302 Television restoration

Quote:
Originally Posted by 19Seventy7 View Post

Quote:
Dejavu indeed I am sure we have had this conversation once before in your G8 thread
This thread has actually taught me a lot, so thank you all, and that I've also done it wrong in the G8, while they are technically in parallel, I'd misunderstood how it works and had connected the negative leads together, but thread each positive lead of each cap into the two PCB holes, so the negative leads aren't in circuit - I did wonder how it'd work like that...

I'll soon be going over that error.

'77
Sorry to distract from this thread, however if you have connected the G8 ones the way you have said you have above, then they are in series not parallel, by connecting them back to back the way you said you have created a Bipolar cap
, which it is fine as it stands if that what is what was desired (I would need to re-read that thread), they will be about half the value of each individual capacitor if the values are nominally equal.

If there is anything you are unsure about please don't be afraid to ask! the only foolish question is the one you don't ask!
None of us were born with knowledge, it was learned by mistakes and by asking questions, you need to be able to crawl before you can walk.
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Old 15th Jul 2021, 12:11 am   #62
19Seventy7
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Default Re: GEC BT302 Television restoration

No not a problem, it's somewhat relevant and it's definitely helpful. I'd made the exact same mistake as in this GEC, but I'll rectify the issue ASAP. I'll definitely ask, I think i might be rushing in a little by trying to do something alone and suffering the consequences because I've little knowledge on parts.

But on a really good note. I replaced the 0.47uF cap with 0.1uF and ta-da!

There's some little niggling faults but all should be easy enough to fix.

So far I'm pleased with the results, thanks all for the help, it's really appreciated

'77
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Old 15th Jul 2021, 9:00 am   #63
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Default Re: GEC BT302 Television restoration

Quite a good picture. Just needs centering up with the shift adjuster mounted on the scan coil assembly.
The BT302 series is an excellent chassis to learn a lot from. The printed boards are easily removable and are marked with all the component numbers, so with the aid of the service manual they can be confidently replaced. John.
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Old 15th Jul 2021, 4:10 pm   #64
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Default Re: GEC BT302 Television restoration

It's all part of a very long learning curve. television receivers are far more critical when it comes to component values than a Broadcast Receiver particularly in the timebase circuits.

This is why it is important to double check everything and if you are fairly new to electronic circuits it will be much easier to fault find if you replace the very minimum of components, preferably one at a time switching on to check the progress.

When things go wrong you must ask yourself 'What have I done?' Unless you are very experienced and with me it has taken 60 years and I still learn something most days and still make silly mistakes. You can imagine what can happen if you are new to the game, you clean everything, break everything and put components on the wrong solder tags. Dust and grot will not stop a TV or Radio from working. Get something on the screen as quickly as possible. It will then show you what is needed.

Just take it slow and easy. Take plenty of digital pictures, they cost nothing and obtain the correct service information from the site at the top of the page, or if not available a call to the guys here can usually turn something up. There appears to be a large number of the GEC BT302 series that have survived. John.
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Old 16th Jul 2021, 12:38 am   #65
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Default Re: GEC BT302 Television restoration

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Originally Posted by Heatercathodeshort View Post
Quite a good picture. Just needs centering up with the shift adjuster mounted on the scan coil assembly.
The BT302 series is an excellent chassis to learn a lot from. The printed boards are easily removable and are marked with all the component numbers, so with the aid of the service manual they can be confidently replaced. John.
I've centred the image as best as I could, it's not quite perfect but I'm not quite finished with it. I've really enjoyed working on this set, as you say it's easy to work on, I was surprised at how simple it was when I got it.

Though I did miss a few Hunts hidden around the frame work, they're gone now though. Yet to do the tuner caps.

Quote:
It's all part of a very long learning curve. television receivers are far more critical when it comes to component values than a Broadcast Receiver particularly in the timebase circuits.

This is why it is important to double check everything and if you are fairly new to electronic circuits it will be much easier to fault find if you replace the very minimum of components, preferably one at a time switching on to check the progress.

When things go wrong you must ask yourself 'What have I done?' Unless you are very experienced and with me it has taken 60 years and I still learn something most days and still make silly mistakes. You can imagine what can happen if you are new to the game, you clean everything, break everything and put components on the wrong solder tags. Dust and grot will not stop a TV or Radio from working. Get something on the screen as quickly as possible. It will then show you what is needed.

Just take it slow and easy. Take plenty of digital pictures, they cost nothing and obtain the correct service information from the site at the top of the page, or if not available a call to the guys here can usually turn something up. There appears to be a large number of the GEC BT302 series that have survived. John.
It definitely is, i think jumping into the deep end of colour television didn't exactly help, should've stuck with baby steps..

I was pretty confident I had got it right with this set as I had done them all one by one, and it seems I was spot on with the exception of the two caps.

I'm actually slightly surprised that the TV circuitry is more critical than broadcast, would never have guessed that really. Now I've given it a moments thought, it makes sense to me in that it has to create a picture out of practically nothingness.

I've actually stumbled across a TV engineering guide on youtube that was uploaded a couple months ago, so I'm going to watch that and study a little bit before steaming ahead with other things. I'm really hoping it'll teach me to read more complex circuit diagrams because I have no idea how.

I can see why so many of these sets still exist, They're lovely sets to look at and so far what I can tell have nice pictures. I've been pleasantly surprised with how good 405 lines can look. I don't think I've seen a picture do it justice, other than a video i saw where 405 lines was much sharper than a 625 line image.

I couldn't resist watching the top of the pops intro on it as I wanted to see what it could do

********************a/3XVC31Z

I'm pleased so far

Thanks
'77
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